cnidarian

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Giant Siponophore 

(Praya dubia)

is a large species of  deep sea colonial hydrozoan of the family Prayidae. Found in  extremely deep South Atlantic waters. Their name of giant holds up as the are one of the largest invertebrates alive to day growing up to 160 ft long! (rivaled only by the bootlace worm at 180ft). This animal has a long string of small circle-like bells which make up most of the body, these are the stinging cells that are a trademark of cnidarians, a sting from P.dubia will cause paralysis or death. At the front? of the animal is a dome like bell which houses the animals nectosome (swimming bells). they like their Man o war relatives are hunters and use a blue bioluminescence to attract prey which it then kills with its stinging cells. Don’t expect to see one of these animals anywhere other than 2-3000 ft down as their hydrostatic skeleton will burst if brought to the surface.

Phylogeny

Animalia-Cnidaria-Hydrozoa-Siphonophora-Prayidae-Praya-dubia

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Jellyfish eyes

more than just water and goo

Most people think of jellyfish as primitive floating balls of jelly and water that aren’t good at anything but stinging people. And while it is true that most jellyfish aren’t exactly “advanced” as far as animals go one class of jellies takes it to the next level. Box Jellies or Sea Wasps are cnidarians of the class cubozoa. Named after their umbrella shaped medusae these small jellies are the one of the most venomous animals in the world. They are also the most developed as they sport a nerve ring and 24 sets of eyes which are located at the base of the bell. Most of these eyes do simple tasks like distinguished between light and dark. But amazingly they also have eight pairs of highly developed, almost human like, eyes which can detect the size and color of different objects. With these eyes the jellyfish can not only navigate its ocean environment with ease but it can also detect and avoid different obstacles. 

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